From aeb165243b20b0945d01b3c0d540dbc969526a99 Mon Sep 17 00:00:00 2001
From: Seth Bromberger <sbromberger@users.noreply.github.com>
Date: Wed, 22 Aug 2018 08:47:11 -0700
Subject: [PATCH] SimpleGraph(SimpleGraph) plus tests. (#998)

---
 src/SimpleGraphs/simplegraph.jl   |  3 +++
 test/simplegraphs/simplegraphs.jl | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/src/SimpleGraphs/simplegraph.jl b/src/SimpleGraphs/simplegraph.jl
index 0abb6003f..05f7dbc0e 100644
--- a/src/SimpleGraphs/simplegraph.jl
+++ b/src/SimpleGraphs/simplegraph.jl
@@ -21,6 +21,9 @@ end
 # SimpleGraph()
 SimpleGraph() = SimpleGraph{Int}()
 
+# SimpleGraph of a SimpleGraph
+SimpleGraph(g::SimpleGraph) = copy(g)
+
 # SimpleGraph(6), SimpleGraph(0x5)
 SimpleGraph(n::T) where T <: Integer = SimpleGraph{T}(n)
 
diff --git a/test/simplegraphs/simplegraphs.jl b/test/simplegraphs/simplegraphs.jl
index 2f4523c26..625b66831 100644
--- a/test/simplegraphs/simplegraphs.jl
+++ b/test/simplegraphs/simplegraphs.jl
@@ -166,6 +166,16 @@ import Random
         @test @inferred(has_edge(g, e))
     end
 
+    gx = CompleteGraph(4)
+    for g in testgraphs(gx)
+        h = Graph(g)
+        @test g == h
+        @test rem_vertex!(g, 2)
+        @test nv(g) == 3 && ne(g) == 3
+        @test g != h
+    end
+
+
     gdx = CompleteDiGraph(4)
     for g in testdigraphs(gdx)
         h = DiGraph(g)